1. Field of the Invention
The present invention relates to an apparatus and method for quantitatively extruding food material and the like by a piston, and more particularly to an apparatus and method for quantitatively extruding fluid food material such as cream or jam, solid food material such as vegetables, fruit, or pieces of cooked fish meat, and a cooked food comprising the solid food material and paste or the like from a nozzle to inject into bread or confectionery.
2. Description of Prior Art
There has been provided an apparatus for injecting food material and the like into an article, in which a hopper, a nozzle, and a cylinder containing a piston are disposed around a valve mechanism. When the valve is arranged to communicate the hopper and the cylinder, the food material in the hopper can be sucked into the cylinder by retracting the piston, and the sucked material, can then be extruded from the cylinder nozzle by arranging the valve to communicate the cylinder and the nozzle and advancing the piston. In this apparatus, however, the material cannot be sucked into the cylinder except for certain kinds of materials which are relatively fluid. That is, less-fluid materials or materials in which a large amount of solid is mixed or which consist only of solid can not be sucked, because if the passage from the hopper to the cylinder is made wider, suction becomes weak, while if it is made sufficiently narrow for suction purposes, clogging occurs.
A screw feeder for extruding food material has also been provided, in which plastic food material, namely, less fluid food material is effectively extruded, but the material could not be extruded in a sufficiently quantitative manner. This screw feeder, of course, is not applicable to materials consisting only of solid.
These apparatuses can handle solid materials only if they are very soft or if they are very small and mixed with other fluid materials.